Pedigree Charts - Biology Worksheets (Page 3 of 3) in pdf

Pedigree Charts - Biology Worksheets Page 3

NAME_________________________________PERIOD_________DATE_____________________

QUESTIONS (Create a Punnett Square to determine the answer for each question)

1. From your results, what is Grandma’s genotype? ____________________

2. What must be the genotypes of their children?

We know that Grandpa Chadwick is homozygous recessive.

3. If Grandma were homozygous dominant, could any homozygous recessive children be produced

from Grandma and Grandpa?

4. If Grandma was heterozygous, could any homozygous recessive children be produced from

them?

SEX-LINKED INHERITANCE - COLORBLINDNESS

To complete this part of the activity, you will need to make a copy of your Pedigree 3 chart. (Do not fill

in any circles or squares)

Remember to determine the genotypes of those possessing the sex-linked trait first. From there, using

Punnett squares, you should be able to determine the genotypes of most, if not all of the family.

Neither Grandma nor Grandpa Chadwick is colorblind.

All of their children have normal color vision, except for Mickey.

Of the grandchildren, the twins both inherited colorblindness, as did their cousins, Barney and Janet.

There still remains one colorblind person in this clan, however, that is up to you to determine who.

Identify the genotype for each individual in the Chadwick family for colorblindness?

CNICHOLS2006

Original Source: Pedigree Chart Activity by Heidi Tither and Melanie Norton

Pedigree Charts - Biology Worksheets Page 3